1. Field of the Invention
The present invention relates generally to a shaft position sensor and, more particularly, to an electro-optical position sensor which generates a light signal and detects a return light signal and which is placed so that substantially only light generated by the sensor is detected by the sensor, thereby limiting potential interference caused by ambient light.
2. Description of the Related Art
Many applications require determining the position or orientation of a rotatable shaft. For example, it is often desirable to determine the position of a rotary actuator shaft. Such position information may be become particularly important during power-up of the rotary actuator. Further, it is often desirable to provide a shaft position sensor which can eliminate electrical and optical inputs which may interfere with accurate readings.
In one specific application, many vehicle test tracks rely on robots to drive vehicles around the test track. The use of robots is particularly relevant for vehicle durability testing in which the vehicle is subjected to very extreme road conditions that result in a sufficiently rough ride. Human drivers would not want to regularly be subjected to such extreme driving conditions. In such vehicles, it is particularly useful to determine the position of the steering shaft in order to facilitate operation of the robotically driven vehicle. Determining the center position of the steering shaft is very useful in such systems, especially at power up.
Thus, it is desirable to provide a steering center indicator device which enables determination of a predetermined position, such as a center position, of a shaft.